1953 Panhead Horn

[billpedalino]

Happy New Year. All !

I purchased a Delco Remy replacement horn for my '53 and noted that the diaphragm, reinforcement ring, center plate, and adjusting screw were cadmium plated rather than black-painted/Parkerized which would be correct for my model year. Because the new replacement horns have black powder coated bodies, for consistency I had the cad plated parts powder coated and the horn looks great. The only problem is that upon reassembly, I can't get the darn thing to work!

It seems like it wants to work, as the diaphragm pulls in, but it wont cycle. I've continuously tried adjusting the diaphragm center screw with no luck - too far in and I get a metallic 'click'. Further out and is seems to want to tone, but still won't cycle. I didn't touch the factory-set air gap setting. Also, I can't find an exploded Delco diagram of the Model 16 horn anywhere, as I'd like to be assured that internal diaphragm pin is situated close to the contact points rather than opposite the points. I definitely should have taken more care during disassembly!

Also, maybe the powder coating applied over the plating is the problem. Has anyone had a similar experience?

Thanks,
Bill Pedalino

[billpedalino]

I've been thinking about this and I believe i have the problem figured out.

The pin on the inside if the diaphragm must act as the mechanical breaker for opening the points each time the diaphragm is pulled in by the magnetized coil. I'll open the horn up again to ensure that this pin ins positioned properly.

I definitely should have taken more care during disassembly!

[T. Cotten]

I know little of them Bill,...

But I do know that powdercoating is notorious for messing with ground connections.

Try a jumper and see if it gets more juice.

Good luck!

....Cotten

[billpedalino]

Cotton,
Fortunately, these units have 2-post connections; hot and ground posts with the ground provided externally trough the horn button; .I'll disassemble and reassemble and report back concerning the diaphragm breaker stud solution.

[pisten-bully]

Bill, Perry Ruiter wrote this up and it may help?

ruiter.ca Horn overhaul treatise.pdf

[billpedalino]

Thanks - I'll print it out and have a look.....

[billpedalino]

Closure to my horn experience;
Perry's write up was quite helpful. What I found is as follows:
The new restoration Delco horn that I had started with had been messed with prior to my receiving it. The flat washer between the diaphragm and ringer was missing and the points set screw had been turned out almost completely. Also, the gaskets between the horn body and diaphragm were missing. I bought this over the web, and it looks like someone had their 'unknowledgeable' fingers in it at some point.
While I was messing with this horn, and in absence of any Delco Remy information (like an exploded diagram), the Delco horns again became available from Ted so I purchased another. Upon disassembly of the 2nd unit, I noticed what parts were missing from the first unit. I also noticed obvious differences in the internal components between he two horns, leading me to think that somebody might be counterfeiting the Delco horns.
However, after speaking with Cimerron cycle, who also retails these horns, I learned that Delco has little to do with their manufacture and apparently just sets minimal standards to which their subcontractors must adhere. This seems plausible, as the two horns that I have were obviously manufactured by different companies.
I disassembled the the 2nd unit (from Ted), painted the diaphragm, external diaphragm reinforcement ring, and ringer plate, stripped and parkerized the body's carriage bolts and reassembled it. Using Perry's instructions and Bruce Palmer's write-up as guides, I tinkered around the points setting and air gap until I got the Vtwin/Delco horn to work correctly.
Finally, I reassembled the original horn using the powder coated diaphragm and ringer and the cadmium plated reinforcement ring (incorrect for 1953). I also removed the powder coating from the diaphragm's inside surface where it touches the body, as this changes the point screw setting. I messed around with it for awhile and eventually got it working as well.
It was a tedious process, but I learned about these simple mechanisms, something I never would have patience for 50 years ago! - They're really just simple relays. And now I have a spare for stock or to sell.
Thank you both for your input, above.
Bill Pedalino